Marlin 4570 load data

stumo

stumo

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Does anyone have concrete load data for 45-70 500gr soft cast gas check? Google searches have landed me with some conflicting info regarding pressures. These will be used in a 18" Marlin 1895 guide gun
 
There are 3 "grades" of .45-70 loadings. The lowest is for 1873 Springfield trapdoors (18,000 CUP max). The top is for Ruger #1 & #3 single shots (up to 40,000 CUP).
You want the middle grade for modern levers that stays under 28,000 CUP.
Look for load data that includes IMR-4198 in the 33 to 38 grain range.
 
I've never owned a Marlin in 45-70, but IIRC, pressure concerns had to do with needing to seat 500 grain bullets deeper than normal, depending on the bullet style, to feed through the rifle. Was this your concern? Or you just need legit load data?
Hodgdons is a good site to check out, depending on which powders you use.
 
Alex is spot on. 500 gr in a Marlin will almost surely be a SS/load through the ejection port situation...and once in the gun they have to be shot, The case base will hit the ejector before the bullet snout clears the chamber. You might think that you can just seat the slugs deeper so they clear (as someone already suggested) but the shanks are so long on those big bullets that when seated deep enough, they are far enough into the case that they are entering the part of the case that is thicker metal than case mouth is and one of two things will be the results, one is the body is enlarged enough that they wont chamber or the bullet will be swaged down to fit the chamber (you specified soft bullets) that will cause barrel leading.
 
I used 41 grs H322 behind a 525 gr Bear Tooth Pile Driver bullet in my 95G Marlin - That load will stop a TRAIN ! RJ

The loading data was developed specifically for modern rifles in excellent mechanical condition. It is suitable specifically for both Winchester and Browning 1886 and 1885 rifles and carbines, Ruger No.1 and No.3 rifles and carbines as well as modern production Marlin 1895 lever action rifles, carbines and Guide Guns.

ALWAYS work up to Max Loads ! Reduce by 10% to start !
 
Thanks for the input everyone! OAL isn't an issue, I made a single mockup round tonight to make sure and it feeds and cycles fine, RNFP (jet bullets) has a nice cannelure. My question was more for legit load data, should have clarified originally
 
fingers284 said:
Alex is spot on. 500 gr in a Marlin will almost surely be a SS/load through the ejection port situation...and once in the gun they have to be shot, The case base will hit the ejector before the bullet snout clears the chamber. You might think that you can just seat the slugs deeper so they clear (as someone already suggested) but the shanks are so long on those big bullets that when seated deep enough, they are far enough into the case that they are entering the part of the case that is thicker metal than case mouth is and one of two things will be the results, one is the body is enlarged enough that they wont chamber or the bullet will be swaged down to fit the chamber (you specified soft bullets) that will cause barrel leading.
Click to expand...

Some 500gr bullets are made specifically for 45-70 lever guns. The nose is the same profile as lighter bullets and the shank is indeed longer. Remember also the 45-70 case is slightly tapered. I've sold 20,000 or so of the levergun style RNFP 500gr bullets. They work fine through the mag, chamber and shoot fine.

OP, you can safely use jacketed bullet data for cast bullets in this application. Cast bullets create lower pressure than jacketed bullets of the same weight, everything else being equal. 1500 fps is about the most you can get with the 500gr bullet in a 45-70.
 
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Hodgdon 25th Reloading Manual, for Marlin and Ruger with 500gr bullets:


H4198: start 39 Max 43.0
H335: Start 49 max 53
H322: start 46 max 50.0
 
I’m a recoil wimp.....

I’m aversive to getting beat up and TBI (Terminal Brain Injury) so the 300 grain Campro booolits are gonna work for me. I did order a 200 round count shipment of 350 grain Single Lube Channel, Round Nose, Flat point boooolits....

Now to get working on some loads with IMR 4320 that I’ve got sitting around. :cool:

Enjoy the the .45-70 blaster addiction!



112CE52C-65E3-422F-9A2E-F0A159225815.jpg



I love this caliber. It sure is a tonne of fun reloading light loads, medium loads, and 405 grain bear blasters!!

Peace Be To Journey!

Cheers, Barney
 

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tactical lever said:
What do you mean by this? Is that a reloading manual that is saying the Marlin 1895 can handle Ruger #1 loads?
Click to expand...
Some reloading manuals have 3 categories of 45-70 load pressure:
1. Trapdoor,
2. Marlin 1895 /Winchester 1886
3. Ruger #1

Some other reloading manuals put the Ruger #1 with the lever guns. In this case the manual is saying the loads listed are safe in both, which is not the same as saying the Marlin can handle the same pressure as the Ruger.
 
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